Non-magnetic, austenitic stainless steels have been developed in recent years to meet the needs of applications and equipment requiring material having low relative magnetic permeability, such as in the medical instrument industry, oil field industry for deep drilling, electrical industry, etc.
Although stainless steels are relatively corrosion resistant in many conditions, certain environments render the material more susceptible to a variety of corrosive effects. For example, in oil field drilling and natural gas exploration, the environment of use includes a high chloride content due to sea water. In such working environments, pitting corrosion can occur, a localized form of corrosion. Pitting corrosion can occur or be accelerated in environments containing halides, for example chloride-rich sea water, fluorides, and iodides; and other anions such as thiosulfates. Additionally, stainless steel, like other high-strength alloys, is susceptible to corrosion fatigue due to exposure to a corrosive environment. Pitting can also contribute to corrosion fatigue.
There remains a need in the art for non-magnetic stainless steel having improved corrosion resistance, specifically pitting corrosion resistance and corrosion fatigue resistance.